1. Unpredictable Software-based Attestation Solution for Node Compromise Detection in Mobile WSN Xinyu Jin 1 Pasd Putthapipat 1 Deng Pan 1 Niki Pissinou 1 S. Kami Makki 2 1 Department of Electrical & Computer Engineering Florida International University 2 Department of Computer Science Lamar University IEEE Globecom 2010, 12/06/2010

2. Outline  Introduction  USAS Procedure  Simulation Result and Analysis  Summary and future work

3. Introduction USAS Procedure Simulation Result and Analysis Summary and future work What is the problem? What are we going to do? Problem Statement  Node compromise Attackers take control of a node in the network (WSN)  Mobile WSNs New challenges regarding to security issues  Node compromise detection Detect compromised nodes

4. Introduction USAS Procedure Simulation Result and Analysis Summary and future work What is the problem? What are we going to do?  Seshadri et. al propose to use pseudorandom memory traversal to detect memory manipulation (SWATT). Deviations from the memory contents referring to an expected value result in the detection of tampering.  Yang et. al apply SWATT in WSNs and improve it by decreasing iterations of memory traversal and deployed attestation schemes in distributed WSNs [11]. Stationary sensor networks Power consumption

5. Introduction USAS Procedure Simulation Result and Analysis Summary and future work What is the problem? What are we going to do?  Unpredictable Software-based Attestation Solution (USAS) Design an efficient software-based attestation with reduced energy consumption for battery-powered nodes. Create dynamic attestation chains to achieve the unpredictability of node verification to avoid creating areas of greater susceptibility in the network. Detect compromised nodes which are one hop away from the base station in mWSNs where the nodes are moving around without fixed neighbors.

6. Introduction USAS Procedure Simulation Result and Analysis Summary and future work USAS overview Memory checksum computing Checksum result verification USAS overview USAS applies a dynamic node chain which is composed of one Initiator node (I-node) and multiple Follower nodes (F-nodes) to conduct attestation. The base station acts as the external verifier and initializes the attestation.  Dynamic node attestation chain  Node mobility consideration

7. Introduction USAS Procedure Simulation Result and Analysis Summary and future work USAS overview Memory checksum computing Checksum result verification Checksum computing  Message authentication one way hash function computing is requested before running the memory traversal function  Memory traversal function applies pseudorandom memory traversal. designs different methods to generate memory access address for I-nodes and F-nodes.

8. Introduction USAS Procedure Simulation Result and Analysis Summary and future work USAS overview Memory checksum computing Checksum result verification The base station uses the same memory traversal seed to compute memory checksums based on the original program memory pattern of each node.

9. Introduction USAS Procedure Simulation Result and Analysis Summary and future work Memory Traversal Function Testing Computing Improvement Analysis Node Compromise Detection Rate Analysis Memory traversal function testing Frequency description of the number of checksum 16KB memory 1bit-16KB change 100,000 iteration

10. Introduction USAS Procedure Simulation Result and Analysis Summary and future work Memory Traversal Function Testing Computing Improvement Analysis Node Compromise Detection Rate Analysis Computing improvement Time consumption (s) Number of F-nodes in the attestation chain Computation time comparison based on 100,000 iterations F-nodes take 12 clock cycles in each round to update a checksum value for a single memory block in USAS. As a comparison, in SWATT, attesting each node takes 23 clock cycles.

11. Introduction USAS Procedure Simulation Result and Analysis Summary and future work Memory Traversal Function Testing Computing Improvement Analysis Node Compromise Detection Rate Analysis Detection rate Detection Rate Probability for a node to be compromised (P c ) Detection rate with k=n/2

12. Introduction USAS Procedure Simulation Result and Analysis Summary and future work Summary Future work Summary USAS  Reduces Time and Power Consumption  Applies dynamic Node Chain for Unpredictable Attestation The role of each node may vary in each time attestation.  Applies Node Compromise Detection Solution in mWSN Limited to one-hop communication

13. Introduction USAS Procedure Simulation Result and Analysis Summary and future work Summary Future work Next step  More simulations built in mobile network simulators and realistic mWSN implementations need to be conducted.  Proper dynamic node chain for multi-hop communications need to be designed.

14. Thank you for your kind attention. Questions? IEEE Globecom 2010, 12/06/2010